Physicians have several treatment methods available to treat various ailments throughout the cardiovascular system and other biological spaces. One exemplary ailment is atherosclerosis, which is a buildup of fatty deposits on the inner walls of vascular lumens. Over time, however, this buildup can lead to stenosis, i.e., narrowing of the vessel, and reduced blood flow. Reduction in blood flow can cause ischemia which can, in turn, manifest itself as angina, stroke, myocardial infarction, hypertension, etc. Various treatments are used to restore blood flow.
One treatment option is bypass surgery, in which a healthy vessel is used to replace the section of vessel where the plaque is occluding flow. This method is highly invasive and requires extensive recuperation.
Exemplary minimally invasive treatment options to address atherosclerosis include angioplasty, stenting, and atherectomy. These methods are all aimed at increasing the diameter of the existing vessel in order to restore or increase blood flow through the occluded section. Angioplasty and stenting involve compressing, or diametrically displacing, the plaque. This displacement of plaque increases the effective diameter of the vessel so that blood flow is improved. A shortfall of angioplasty and stenting is that the treated vessel can re-stenose over time. Restenosis is the result of the biological response caused by mechanical stretching of the vessel that occurs with inflating balloons used in angioplasty and expanding stents. This vessel stretching can also lead to vessel injury, which can in turn cause a vessel to constrict following angioplasty. With the use of stents, intimal thickening can lead to vessel narrowing. Moreover, these known methods do not remove the plaque, but rather simply displace it. In addition, stenting can preclude the use of various treatment options at a future stage and in-stent restenosis can be difficult to treat.
With atherectomy, plaque is removed from the affected vessel by mechanical means, such as sanding or cutting. The challenges with atherectomy methods include the following: unfavorable outcomes in the coronary arteries, limited levels of plaque removal, and potential damage to the artery wall. With limited plaque removal, the potential for restenosis of the artery is significant.
Other exemplary ailments may benefit from treatment devices and/or options throughout the cardiovascular system. As one example, treatment of certain organs or tissue may be accomplished if a vessel (or vessels) that controls blood flow to that area can be isolated to provide targeted and selective delivery of a treatment, as opposed to known systemic treatment options. As another example, it may also be beneficial to have a treatment device that permits isolation of a portion of a heart to treat a calcified heart valve. As yet a further example, it may also be beneficial to isolate a portion of vessel that has an aneurysm to permit removal of blood and/or follow-up treatment.